A new study in the journal Agriculture explored how interchanging sows between different farrowing systems impacted piglet mortality over multiple litters. Initial results demonstrated that sows who returned to the same farrowing system performed better and had decreased piglet mortality. The results also indicated that sows who farrowed in a pen tended to have larger litters than those who used other housing systems.

The researchers used retrospective farm performance records to compare the performance of sows between their first and second farrow. They sorted the sows into either standard farrowing crates, temporary crates or straw-bedded pens. Researchers then compared the size of the litters and the mortality rates in piglets.

Their results indicated that litter size increased and piglet mortality decreased between first and second farrowing. The exceptions to this observation were seen when sows transitioned from a traditional farrowing crate to a temporary crate. This change resulted in higher incidences of crush injuries and mortalities in piglets.

The researchers concluded that sows on commercial farms should be kept in the same farrowing system in order to ensure best results. However, if the sows had to change farrowing systems, the researchers recommend that the systems should be different enough for the sows to discriminate between them. This would encourage them to adjust their natural behaviours to the new setting; and potentially improve piglet mortality.